Abstract：
Fast environmental changes and high coastal human pressures and impacts threaten the Mediterranean Sea. Over the last decade, recurrent blooms of the harmful dinoflagellate Ostreopsis cf. ovata have been recorded in many Mediterranean beaches. These microalgae produce toxins that affect marine organisms and human health. Understanding the environmental conditions that influence the appearance and magnitude of O. cf. ovata blooms, as well as how climate change will modify its future distribution and dynamics, is crucial for predicting and managing their effects. This study investigates whether the spatio-temporal distribution of this microalga and the frequency of its blooms could be altered in future climate change scenarios in the Mediterranean Western basin. For the first time, an ecological habitat model (EHM) is forced by physico-chemical climate change simulations at high-resolution, under the strong greenhouse gas emission trajectory (RCP8.5). It allows to characterize how O. cf. ovata may respond to projected conditions and how its distribution could shift over a wide spatial scale, in this plausible future. Before being applied to the EHM, future climate simulations are further refined by using a statistical adaptation method (Cumulative Distribution Function transform) to improve the predictions robustness. Temperature (optimum 23-26 °C), high salinity (>38 psu) and high inorganic nutrient concentrations (nitrate >0.25 mmol N·m-3 and phosphate >0.035 mmol P·m-3) drive O. cf. ovata abundances. High spatial disparities in future abundances are observed. Namely, O. cf. ovata abundances could increase on the Mediterranean coasts of France, Spain and the Adriatic Sea while a decrease is expected in the Tyrrhenian Sea. The bloom period could be extended, starting earlier and continuing later in the year. From a methodological point of view, this study highlights best practices of EHMs in the context of climate change to identify sensitive areas for current and future harmful algal blooms.
摘要：
快速的环境变化以及沿海人类的高压力和影响威胁着地中海。在过去的十年里，有害的鞭毛藻链球菌的反复开花。在许多地中海海滩上都记录了ovata。这些微藻产生影响海洋生物和人类健康的毒素。了解影响O的外观和大小的环境条件。cf.ovata开花,以及气候变化将如何改变其未来的分布和动态，对于预测和管理它们的影响至关重要。这项研究调查了在地中海西部盆地未来的气候变化情景中，这种微藻的时空分布及其开花频率是否会改变。第一次,生态栖息地模型（EHM）是由高分辨率的物理化学气候变化模拟所强制的，在强温室气体排放轨迹(RCP8.5)下。它允许描述O.cf.ovata可能会对预计的条件以及其分布如何在宽空间尺度上变化做出反应，在这个看似合理的未来。在应用于EHM之前，通过使用统计适应方法（累积分布函数变换）来进一步完善未来的气候模拟，以提高预测的鲁棒性。温度（最佳23-26°C），高盐度（>38psu）和高无机营养素浓度（硝酸盐>0.25mmolN·m-3和磷酸盐>0.035mmolP·m-3）驱动O。参见Ovata丰富。观察到未来丰度的高度空间差异。即,O.cf.在法国的地中海沿岸，ovata的丰度可能会增加，西班牙和亚得里亚海，而第勒尼安海预计会减少。开花期可以延长，从今年早些时候开始，并在今年晚些时候继续。从方法论的角度来看，这项研究强调了EHM在气候变化背景下的最佳实践，以确定当前和未来有害藻华的敏感区域。
